to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351636 91177308-0d34-0410-b5e6-96231b3b80d8
The current llvm.mem.parallel_loop_access metadata has a problem in that
it uses LoopIDs. LoopID unfortunately is not loop identifier. It is
neither unique (there's even a regression test assigning the some LoopID
to multiple loops; can otherwise happen if passes such as LoopVersioning
make copies of entire loops) nor persistent (every time a property is
removed/added from a LoopID's MDNode, it will also receive a new LoopID;
this happens e.g. when calling Loop::setLoopAlreadyUnrolled()).
Since most loop transformation passes change the loop attributes (even
if it just to mark that a loop should not be processed again as
llvm.loop.isvectorized does, for the versioned and unversioned loop),
the parallel access information is lost for any subsequent pass.
This patch unlinks LoopIDs and parallel accesses.
llvm.mem.parallel_loop_access metadata on instruction is replaced by
llvm.access.group metadata. llvm.access.group points to a distinct
MDNode with no operands (avoiding the problem to ever need to add/remove
operands), called "access group". Alternatively, it can point to a list
of access groups. The LoopID then has an attribute
llvm.loop.parallel_accesses with all the access groups that are parallel
(no dependencies carries by this loop).
This intentionally avoid any kind of "ID". Loops that are clones/have
their attributes modifies retain the llvm.loop.parallel_accesses
attribute. Access instructions that a cloned point to the same access
group. It is not necessary for each access to have it's own "ID" MDNode,
but those memory access instructions with the same behavior can be
grouped together.
The behavior of llvm.mem.parallel_loop_access is not changed by this
patch, but should be considered deprecated.
Differential Revision: https://reviews.llvm.org/D52116
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349725 91177308-0d34-0410-b5e6-96231b3b80d8
When converting dbg.declares, if the described value is a [s|z]ext,
refer to the ext directly instead of referring to its operand.
This fixes a narrowing bug (the debugger got the sign of a variable
wrong, see llvm.org/PR35400).
The main reason to refer to the ext's operand was that an optimization
may remove the ext itself, leading to a dropped variable. Now that
InstCombine has been taught to use replaceAllDbgUsesWith (r336451), this
is less of a concern. Other passes can/should adopt this API as needed
to fix dropped variable bugs.
Differential Revision: https://reviews.llvm.org/D51813
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349214 91177308-0d34-0410-b5e6-96231b3b80d8
The `changeToCall` function did not preserve the invoke's metadata.
Currently, there is probably no metadata that depends on being applied
on a CallInst or InvokeInst. Therefore we can replace the instruction's
metadata.
This fixes http://llvm.org/PR39994
Suggested-by: Moritz Kreutzer <moritz.kreutzer@siemens.com>
Differential Revision: https://reviews.llvm.org/D55666
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349170 91177308-0d34-0410-b5e6-96231b3b80d8
Add methods to BasicBlock which make it easier to efficiently check
whether a block has N (or more) predecessors.
This can be more efficient than using pred_size(), which is a linear
time operation.
We might consider adding similar methods for successors. I haven't done
so in this patch because succ_size() is already O(1).
With this patch applied, I measured a 0.065% compile-time reduction in
user time for running `opt -O3` on the sqlite3 amalgamation (30 trials).
The change in mergeStoreIntoSuccessor alone saves 45 million linked list
iterations in a stage2 Release build of llc.
See llvm.org/PR39702 for a harder but more general way of achieving
similar results.
Differential Revision: https://reviews.llvm.org/D54686
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347256 91177308-0d34-0410-b5e6-96231b3b80d8
As K has to dominate I, IIUC I's range metadata must be a subset of
K's. After Eli's recent clarification to the LangRef, loading a value
outside of the range is undefined behavior.
Therefore if I's range contains elements outside of K's range and we would load
one such value, K would cause undefined behavior.
In cases like hoisting/sinking, we still want the most generic range
over all code paths to/from the hoist/sink point. As suggested in the
patches related to D47339, I will refactor the handling of those
scenarios and try to decouple it from this function as follow up, once
we switched to a similar handling of metadata in most of
combineMetadata.
I updated some tests checking mostly the merging of metadata to keep the
metadata of to dominating load. The most interesting one is probably test8 in
test/Transforms/JumpThreading/thread-loads.ll. It contained a comment
about the alias metadata preventing us to eliminate the branch, but it
seem like the actual problem currently is that we merge the ranges of
both loads and cannot eliminate the icmp afterwards. With this patch, we
manage to eliminate the icmp, as the range of the first load excludes 8.
Reviewers: efriedma, nlopes, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D51629
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345456 91177308-0d34-0410-b5e6-96231b3b80d8
by `getTerminator()` calls instead be declared as `Instruction`.
This is the biggest remaining chunk of the usage of `getTerminator()`
that insists on the narrow type and so is an easy batch of updates.
Several files saw more extensive updates where this would cascade to
requiring API updates within the file to use `Instruction` instead of
`TerminatorInst`. All of these were trivial in nature (pervasively using
`Instruction` instead just worked).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344502 91177308-0d34-0410-b5e6-96231b3b80d8
This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.
All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340701 91177308-0d34-0410-b5e6-96231b3b80d8
The core get and set routines move to the `Instruction` class. These
routines are only valid to call on instructions which are terminators.
The iterator and *generic* range based access move to `CFG.h` where all
the other generic successor and predecessor access lives. While moving
the iterator here, simplify it using the iterator utilities LLVM
provides and updates coding style as much as reasonable. The APIs remain
pointer-heavy when they could better use references, and retain the odd
behavior of `operator*` and `operator->` that is common in LLVM
iterators. Adjusting this API, if desired, should be a follow-up step.
Non-generic range iteration is added for the two instructions where
there is an especially easy mechanism and where there was code
attempting to use the range accessor from a specific subclass:
`indirectbr` and `br`. In both cases, the successors are contiguous
operands and can be easily iterated via the operand list.
This is the first major patch in removing the `TerminatorInst` type from
the IR's instruction type hierarchy. This change was discussed in an RFC
here and was pretty clearly positive:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123407.html
There will be a series of much more mechanical changes following this
one to complete this move.
Differential Revision: https://reviews.llvm.org/D47467
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340698 91177308-0d34-0410-b5e6-96231b3b80d8
This patch makes the DoesKMove argument non-optional, to force people
to think about it. Most cases where it is false are either code hoisting
or code sinking, where we pick one instruction from a set of
equal instructions among different code paths.
Reviewers: dberlin, nlopes, efriedma, davide
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D47475
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@340606 91177308-0d34-0410-b5e6-96231b3b80d8
In combineMetadata, we should be able to preserve K's nonnull metadata,
if K does not move. This condition should hold for all replacements by
NewGVN/GVN, but I added a bunch of assertions to verify that.
Fixes PR35038.
There probably are additional kinds of metadata that could be preserved
using similar reasoning. This is follow-up work.
Reviewers: dberlin, davide, efriedma, nlopes
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D47339
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339149 91177308-0d34-0410-b5e6-96231b3b80d8
This function is shared between both implementations. I am not sure if
Utils/Local.h is the best place though.
Reviewers: davide, dberlin, efriedma, xbolva00
Reviewed By: efriedma, xbolva00
Differential Revision: https://reviews.llvm.org/D47337
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339138 91177308-0d34-0410-b5e6-96231b3b80d8
In the past, DbgInfoIntrinsic has a strong assumption that these
intrinsics all have variables and expressions attached to them.
However, it is too strong to derive the class for other debug entities.
Now, it has problems for debug labels.
In order to make DbgInfoIntrinsic as a base class for 'debug info', I
create a class for 'variable debug info', DbgVariableIntrinsic.
DbgDeclareInst, DbgAddrIntrinsic, and DbgValueInst will be derived from it.
Differential Revision: https://reviews.llvm.org/D50220
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338984 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Previously, `removeUnreachableBlocks` still returns true (which indicates the CFG is changed) even when all the unreachable blocks found is awaiting deletion in the DDT class.
This makes code pattern like
```
// Code modified from lib/Transforms/Scalar/SimplifyCFGPass.cpp
bool EverChanged = removeUnreachableBlocks(F, nullptr, DDT);
...
do {
EverChanged = someMightHappenModifications();
EverChanged |= removeUnreachableBlocks(F, nullptr, DDT);
} while (EverChanged);
```
become a dead loop.
Fix this by detecting whether a BasicBlock is already awaiting deletion.
Reviewers: kuhar, brzycki, dmgreen, grosser, davide
Reviewed By: kuhar, brzycki
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49738
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338882 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This patch is the second in a series of patches related to the [[ http://lists.llvm.org/pipermail/llvm-dev/2018-June/123883.html | RFC - A new dominator tree updater for LLVM ]].
It converts passes (e.g. adce/jump-threading) and various functions which currently accept DDT in local.cpp and BasicBlockUtils.cpp to use the new DomTreeUpdater class.
These converted functions in utils can accept DomTreeUpdater with either UpdateStrategy and can deal with both DT and PDT held by the DomTreeUpdater.
Reviewers: brzycki, kuhar, dmgreen, grosser, davide
Reviewed By: brzycki
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48967
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338814 91177308-0d34-0410-b5e6-96231b3b80d8
LowerDbgDeclare inserts a dbg.value before each use of an address
described by a dbg.declare. When inserting a dbg.value before a CallInst
use, however, it fails to append DW_OP_deref to the DIExpression.
The DW_OP_deref is needed to reflect the fact that a dbg.value describes
a source variable directly (as opposed to a dbg.declare, which relies on
pointer indirection).
This patch adds in the DW_OP_deref where needed. This results in the
correct values being shown during a debug session for a program compiled
with ASan and optimizations (see https://reviews.llvm.org/D49520). Note
that ConvertDebugDeclareToDebugValue is already correct -- no changes
there were needed.
One complication is that SelectionDAG is unable to distinguish between
direct and indirect frame-index (FRAMEIX) SDDbgValues. This patch also
fixes this long-standing issue in order to not regress integration tests
relying on the incorrect assumption that all frame-index SDDbgValues are
indirect. This is a necessary fix: the newly-added DW_OP_derefs cannot
be lowered properly otherwise. Basically the fix prevents a direct
SDDbgValue with DIExpression(DW_OP_deref) from being dereferenced twice
by a debugger. There were a handful of tests relying on this incorrect
"FRAMEIX => indirect" assumption which actually had incorrect
DW_AT_locations: these are all fixed up in this patch.
Testing:
- check-llvm, and an end-to-end test using lldb to debug an optimized
program.
- Existing unit tests for DIExpression::appendToStack fully cover the
new DIExpression::append utility.
- check-debuginfo (the debug info integration tests)
Differential Revision: https://reviews.llvm.org/D49454
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338069 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The optimizer is 10%+ slower with vs without debuginfo. I started checking where
the difference is coming from.
I compiled sqlite3.c with and without debug info from CTMark and compare the time difference.
I use Xcode Instrument to find where time is spent. This brings about 20ms, out of ~20s.
Reviewers: davide, hfinkel
Reviewed By: hfinkel
Subscribers: hfinkel, aprantl, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D49337
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337416 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: efriedma, george.burgess.iv
Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits
Differential Revision: https://reviews.llvm.org/D47895
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336613 91177308-0d34-0410-b5e6-96231b3b80d8
The replaceAllDbgUsesWith utility helps passes preserve debug info when
replacing one value with another.
This improves upon the existing insertReplacementDbgValues API by:
- Updating debug intrinsics in-place, while preventing use-before-def of
the replacement value.
- Falling back to salvageDebugInfo when a replacement can't be made.
- Moving the responsibiliy for rewriting llvm.dbg.* DIExpressions into
common utility code.
Along with the API change, this teaches replaceAllDbgUsesWith how to
create DIExpressions for three basic integer and pointer conversions:
- The no-op conversion. Applies when the values have the same width, or
have bit-for-bit compatible pointer representations.
- Truncation. Applies when the new value is wider than the old one.
- Zero/sign extension. Applies when the new value is narrower than the
old one.
Testing:
- check-llvm, check-clang, a stage2 `-g -O3` build of clang,
regression/unit testing.
- This resolves a number of mis-sized dbg.value diagnostics from
Debugify.
Differential Revision: https://reviews.llvm.org/D48676
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336451 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When salvaging a dbg.declare/dbg.addr we should not add
DW_OP_stack_value to the DIExpression
(see test/Transforms/InstCombine/salvage-dbg-declare.ll).
Consider this example
%vla = alloca i32, i64 2
call void @llvm.dbg.declare(metadata i32* %vla, metadata !1, metadata !DIExpression())
Instcombine will turn it into
%vla1 = alloca [2 x i32]
%vla1.sub = getelementptr inbounds [2 x i32], [2 x i32]* %vla, i64 0, i64 0
call void @llvm.dbg.declare(metadata [2 x i32]* %vla1.sub, metadata !19, metadata !DIExpression())
If the GEP can be eliminated, then the dbg.declare will be salvaged
and we should get
%vla1 = alloca [2 x i32]
call void @llvm.dbg.declare(metadata [2 x i32]* %vla1, metadata !19, metadata !DIExpression())
The problem was that salvageDebugInfo did not recognize dbg.declare
as being indirect (%vla1 points to the value, it does not hold the
value), so we incorrectly got
call void @llvm.dbg.declare(metadata [2 x i32]* %vla1, metadata !19, metadata !DIExpression(DW_OP_stack_value))
I also made sure that llvm::salvageDebugInfo and
DIExpression::prependOpcodes do not add DW_OP_stack_value to
the DIExpression in case no new operands are added to the
DIExpression. That way we avoid to, unneccessarily, turn a
register location expression into an implicit location expression
in some situations (see test11 in test/Transforms/LICM/sinking.ll).
Reviewers: aprantl, vsk
Reviewed By: aprantl, vsk
Subscribers: JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D48837
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336191 91177308-0d34-0410-b5e6-96231b3b80d8
Add an overload for the common case where the replacement dbg.values
have the same DIExpressions as the originals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335643 91177308-0d34-0410-b5e6-96231b3b80d8
salvageDebugInfo() performs a check that allows it to exit early without
doing a DenseMap lookup. It's a bit neater and marginally more useful to
sink this early exit into the findDbg{Addr,Users,Values} helpers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335642 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This is a follow-up to r334830 and r335031.
In the valueCoversEntireFragment check we now also handle
the situation when there is a variable length array (VLA)
involved, and the length of the array has been reduced to
a constant.
The ConvertDebugDeclareToDebugValue functions that are related
to PHI nodes and load instructions now avoid inserting dbg.value
intrinsics when the value does not, for certain, cover the
variable/fragment that should be described.
In r334830 we assumed that the value always covered the entire
var/fragment and we had assertions in the code to show that
assumption. However, those asserts failed when compiling code
with VLAs, so we removed the asserts in r335031. Now when we
know that the valueCoversEntireFragment check can fail also for
PHI/Load instructions we avoid to insert the faulty dbg.value
intrinsic in such situations. Compared to the Store instruction
scenario we simply drop the dbg.value here (as the variable does
not change its value due to PHI/Load, so an earlier dbg.value
describing the variable should still be valid).
Reviewers: aprantl, vsk, efriedma
Reviewed By: aprantl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D48547
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335580 91177308-0d34-0410-b5e6-96231b3b80d8
This utility should operate on Values, not Instructions. While I'm here,
I've also made it possible to skip emitting replacement dbg.values for
certain debug users (by having RewriteExpr return nullptr).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335152 91177308-0d34-0410-b5e6-96231b3b80d8
The purpose of this utility is to make it easier for optimizations to
insert replacement dbg.values for instructions they are deleting. This
is useful in situations where salvageDebugInfo is inapplicable, say,
because the new dbg.value cannot refer to an operand of the dying value.
The utility is called insertReplacementDbgValues.
It assumes that the instruction 'From' is going to be deleted, and
inserts replacement dbg.values for each debug user of 'From'. The
newly-inserted dbg.values refer to 'To' instead of 'From'. Each
replacement dbg.value has the same location and variable as the debug
user it replaces, has a DIExpression determined by the result of
'RewriteExpr' applied to an old debug user of 'From', and is placed
before 'InsertBefore'.
This should simplify future patches, like D48331.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335144 91177308-0d34-0410-b5e6-96231b3b80d8
This is a fixup for r334830 causing problems in polly-aosp buildbot.
Focus in r334830 was to fix a problem seen with
ConvertDebugDeclareToDebugValue involving store instructions.
It also added some asserts to find out of similar problems
existed for the ConvertDebugDeclareToDebugValue functions
involving load and phi instructions. One of those asserts seems
to blow in the polly-aosp buildbot, so I'll revert the asserts
while debugging.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335031 91177308-0d34-0410-b5e6-96231b3b80d8
This is r334704 (which was reverted in r334732) with a fix for
types like x86_fp80. We need to use getTypeAllocSizeInBits and
not getTypeStoreSizeInBits to avoid dropping debug info for
such types.
Original commit msg:
> Summary:
> Do not convert a DbgDeclare to DbgValue if the store
> instruction only refer to a fragment of the variable
> described by the DbgDeclare.
>
> Problem was seen when for example having an alloca for an
> array or struct, and there were stores to individual elements.
> In the past we inserted a DbgValue intrinsics for each store,
> just as if the store wrote the whole variable.
>
> When handling store instructions we insert a DbgValue that
> indicates that the variable is "undefined", as we do not know
> which part of the variable that is updated by the store.
>
> When ConvertDebugDeclareToDebugValue is used with a load/phi
> instruction we assert that the referenced value is large enough
> to cover the whole variable. Afaict this should be true for all
> scenarios where those methods are used on trunk. If the assert
> blows in the future I guess we could simply skip to insert a
> dbg.value instruction.
>
> In the future I think we should examine which part of the variable
> that is accessed, and add a DbgValue instrinsic with an appropriate
> DW_OP_LLVM_fragment expression.
>
> Reviewers: dblaikie, aprantl, rnk
>
> Reviewed By: aprantl
>
> Subscribers: JDevlieghere, llvm-commits
>
> Tags: #debug-info
>
> Differential Revision: https://reviews.llvm.org/D48024
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334830 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r334704.
Buildbots detected an assertion in "test tsan in debug compiler-rt build".
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334732 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Do not convert a DbgDeclare to DbgValue if the store
instruction only refer to a fragment of the variable
described by the DbgDeclare.
Problem was seen when for example having an alloca for an
array or struct, and there were stores to individual elements.
In the past we inserted a DbgValue intrinsics for each store,
just as if the store wrote the whole variable.
When handling store instructions we insert a DbgValue that
indicates that the variable is "undefined", as we do not know
which part of the variable that is updated by the store.
When ConvertDebugDeclareToDebugValue is used with a load/phi
instruction we assert that the referenced value is large enough
to cover the whole variable. Afaict this should be true for all
scenarios where those methods are used on trunk. If the assert
blows in the future I guess we could simply skip to insert a
dbg.value instruction.
In the future I think we should examine which part of the variable
that is accessed, and add a DbgValue instrinsic with an appropriate
DW_OP_LLVM_fragment expression.
Reviewers: dblaikie, aprantl, rnk
Reviewed By: aprantl
Subscribers: JDevlieghere, llvm-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D48024
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334704 91177308-0d34-0410-b5e6-96231b3b80d8
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333954 91177308-0d34-0410-b5e6-96231b3b80d8
be both simpler and substantially more efficient.
Rather than use a hand-rolled iteration technique that isn't quite the
same as RPO, use the pre-built RPO loop body traversal utility.
Once visiting the loop body in RPO, we can assert that we visit defs
before uses reliably. When this is the case, the only need to iterate is
when simplifying a def that is used by a PHI node along a back-edge.
With this patch, the first pass over the loop body is just a complete
simplification of every instruction across the loop body. When we
encounter a use of a simplified instruction that stems from a PHI node
in the loop body that has already been visited (due to some cyclic CFG,
potentially the loop itself, or a nested loop, or unstructured control
flow), we recall that specific PHI node for the second iteration.
Nothing else needs to be preserved from iteration to iteration.
On the second and later iterations, only instructions known to have
simplified inputs are considered, each time starting from a set of PHIs
that had simplified inputs along the backedges.
Dead instructions are collected along the way, but deleted in a batch at
the end of each iteration making the iterations themselves substantially
simpler. This uses a new batch API for recursively deleting dead
instructions.
This alsa changes the routine to visit subloops. Because simplification
is fundamentally transitive, we may need to visit the entire loop body,
including subloops, to handle knock-on simplification.
I've added a basic test file that helps demonstrate that all of these
changes work. It includes both straight-forward loops with
simplifications as well as interesting PHI-structures, CFG-structures,
and a nested loop case.
Differential Revision: https://reviews.llvm.org/D47407
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333461 91177308-0d34-0410-b5e6-96231b3b80d8
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332240 91177308-0d34-0410-b5e6-96231b3b80d8
This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.
Differential Revision: https://reviews.llvm.org/D46668
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332057 91177308-0d34-0410-b5e6-96231b3b80d8
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is
!DILabel(scope: !1, name: "foo", file: !2, line: 3)
We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is
llvm.dbg.label(metadata !1)
It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.
We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.
Differential Revision: https://reviews.llvm.org/D45024
Patch by Hsiangkai Wang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331841 91177308-0d34-0410-b5e6-96231b3b80d8
Inspired by r331508, I did a grep and found these.
Mostly just change from dyn_cast to cast. Some cases also showed a dyn_cast result being converted to bool, so those I changed to isa.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331577 91177308-0d34-0410-b5e6-96231b3b80d8
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46290
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331272 91177308-0d34-0410-b5e6-96231b3b80d8
This patch adds support for fragment expressions
TryToShrinkGlobalToBoolean() which were previously just dropped.
Thanks to Reid Kleckner for providing me a reproducer!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@331086 91177308-0d34-0410-b5e6-96231b3b80d8
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.
Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.
Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328165 91177308-0d34-0410-b5e6-96231b3b80d8
